Readdir ls -f graphs

From Linux NFS

    36: Linux 2.6.36
36NORC: Linux 2.6.36 (without readdir cap)
    38: Linux 2.6.38
  38RC: Linux 2.6.38 (with readdir cap added back)
  38NB: Linux 2.6.38 (with Neil Brown's patch and loop detection)

Real

NFS v3

• 
  • 2.6.36 based kernels seem to be slightly slower than 2.6.38 based kernels.
• 
  • 2.6.38 performs the same as 2.6.36 with the readdir plus cap removed. Using readdir rather than readdir plus is faster in this case.

NFS v4

• 
  • 2.6.36 based kernels take more time to finish the command than 2.6.38 based kernels.
• 
  • 2.6.38 based kernels can complete this command much faster than 2.6.36 based kernels.

Sys

NFS v3

• 
• 
  • Using readdir plus for this command takes longer than using a simple readdir.

NFS v4

• 
• 
  • Unmodified 2.6.38 gives the worst performance here. All other kernels seem to give roughly the same results.

RPC ops

NFS v3

• 
  • 2.6.36 kernels issue fewer RPC operations than 2.6.38 kernels
• 
  • Kernels with readdir plus limiting seem to have fewer RPC operations than kernels without the limit.

NFS v4

• 
  • 2.6.36 based kernels issue fewer RPC calls than 2.6.38 kernels.
• 
  • 2.6.36 based kernels give the fewest number of RPC calls. 2.6.38 with readdir plus limiting issues a few hundred more RPC operations, but not nearly as much as an unmodified 2.6.38 kernel.